Embodiments of the present specification relate to sample transfer, and more particularly to automated sample transfer.
In manufacturing of recombinant proteins from mammalian cells, seed train expansion of cryo-preserved cells is a significant step required to initiate a new production campaign. This scale-up process or seed train expansion is significant since the quality of an inoculum often determines the success of the production campaign.
Typically, in a seed train expansion process, cells (such as cells for protein therapies) are initially cultured from a small volume (e.g., 1-ml or more) of a cryo-preserved sample. In an example, the sample to be cryo-preserved is placed in a cryo-vial and cooled down to a cryo cooling temperature of about −80° C. or below to preserve the cells in the sample. Further, when required for inoculation, a small volume of about 1.0 ml to about 5.0 ml of the cryo-preserved sample is thawed to obtain a suspension of cells in the cryo-vial. Subsequently, the thawed sample cells are transferred into traditionally used culture vessels, such as T-flasks or spinner flasks. Additionally, the culture vessels are routinely incubated in a CO2-controlled incubator.
Further, the cells in the culture vessels are mixed with a growth medium to facilitate cell growth. The suspension of the cells is sub-cultivated based on cell growth into an additional culture vessel of the same size or larger cell culture vessels. As the cells grow in quantity, the cells are transferred to increasingly larger volume culture vessels with more growth medium. This process of adding growth medium, cell transfer and cell growth continues until a determined cell mass is obtained. When the determined cell mass is accumulated, the cell suspension is collected and used to inoculate a bioreactor that may be used to start a new production campaign. In one example, the determined cell mass may be used to inoculate the production in vessels such as WAVE™ Bag and Xcellerex™ bioreactors.
Typically, the seed train expansion process requires complex manual operations and use of a plurality of culture vessels, resulting in increased probability of contamination of the cells. In addition, campaign-to-campaign variability of the seed train expansion process may result from the lack of active pH or dissolved oxygen and other similar indicators for control during scale-up.
Usually, the seed train expansion process needs to be carried out by a skilled operator. In initial stages of the cell culture and expansion, the operator needs to thaw the cryo-vial in a water bath or a bead bath. Additionally, the operator needs to decontaminate the outer surface of the vial. By way of example, surface decontamination of the cryo-vial may be performed by spraying chemicals, such as ethanol or bleach solutions. After surface decontamination, the cryo-vial is opened in a laminar hood. Further, a pipette is used to recover the inoculum sample from the cryo-vial and transfer the sample to a flask that is pre-filled with a determined amount of growth medium. Subsequently, the flask is placed into an incubator to complete the initial cell culture operation procedure. Accordingly, the existing process and the set-up associated with the seed train expansion process to initiate cell culture from a cryo-preserved sample of cells are both labor and infrastructure intensive.